2017-09-26T21:57:05ZDevelopment of a multimaterial additive manufacturing process for electronic deviceshttp://hdl.handle.net/2117/107550
Development of a multimaterial additive manufacturing process for electronic devices
Muguruza Blanco, Asier; Bonada Bo, Jordi; Gómez Fernández, Agustín; Minguella Canela, Joaquim; fernandes, joana; Ramos, Francisco; Xuriguera Martin, Elena; Varea Espelt, Aida; Cirera Hernandez, Albert
In order to increase the versatility of additive manufacturing multimaterial processes, a hybrid system has been developed, which is capable of combin ing 3D printing technology by DLP (Digital Light Processing) with a two - dimensional Drop - on - Demand Inkjet printing system. Through DLP technology based on digital micromirror devices (DMDs) it is possible to build up 3D geometries layer - by - layer using polyme rization of photo sensitive resins. Concurrently, while the construction process is performed, the I nk J et printing system is used to deposit tiny drops of conductive inks on the substrate generated, which will thus constitute an electric circuit embedded within the three dimensional structure. On the other hand, photo sensitive resins have been filled with Low Te mperature Co - f iring Ceramic (LT CC) particles , in order to modify the basis properties of the part by using sinterizable slurries. Finally the challenges in the sintering process for achieving functional parts are discussed and a few prototypes have been built in order t o validate this technology
2017-09-12T10:46:57ZMuguruza Blanco, AsierBonada Bo, JordiGómez Fernández, AgustínMinguella Canela, Joaquimfernandes, joanaRamos, FranciscoXuriguera Martin, ElenaVarea Espelt, AidaCirera Hernandez, AlbertIn order to increase the versatility of additive manufacturing multimaterial processes, a hybrid system has been developed, which is capable of combin ing 3D printing technology by DLP (Digital Light Processing) with a two - dimensional Drop - on - Demand Inkjet printing system. Through DLP technology based on digital micromirror devices (DMDs) it is possible to build up 3D geometries layer - by - layer using polyme rization of photo sensitive resins. Concurrently, while the construction process is performed, the I nk J et printing system is used to deposit tiny drops of conductive inks on the substrate generated, which will thus constitute an electric circuit embedded within the three dimensional structure. On the other hand, photo sensitive resins have been filled with Low Te mperature Co - f iring Ceramic (LT CC) particles , in order to modify the basis properties of the part by using sinterizable slurries. Finally the challenges in the sintering process for achieving functional parts are discussed and a few prototypes have been built in order t o validate this technologySurface roughness assessment after different strategy patterns of ultrasonic ball burnishinghttp://hdl.handle.net/2117/107460
Surface roughness assessment after different strategy patterns of ultrasonic ball burnishing
Jerez Mesa, Ramón; Gómez Gras, David; Travieso Rodriguez, Jose Antonio
Ball burnishing is a comprehensive finishing process consisting on deforming plastically a certain surface by the action of a rolling sphere-shaped indenter. In this work, an AISI 1038 workpiece is burnished in two phases. The first phase covers the burnishing of a 10x10 mm patch, performed along the direction of the previous milling. The second pass is applied on the previous patch, following three different strategies, namely, parallel, perpendicular and at a 45-degrees angle with regards to that first burnishing direction. The comparison between the non-vibration assisted ball burnishing (NVABB) and vibration-assisted ball burnishing (VABB) effects is included in the study. To assess the influence of these strategies on the final roughness profile, an L9 Taguchi orthogonal array is designed, including as factors the vibrations amplitude, the burnishing force, and the lateral pass width. Surface roughness is measured and compared to determine the optimal burnishing orientation. The VABB process proves to be more effective in surface roughness improvement. Technical recommendations are given to select the best process parameters inside the tested levels for each factor. All burnishing strategy prove to have different effects on the surface, and should be selected according to the preferential burnishing direction and in service application of the part.
2017-09-06T12:25:51ZJerez Mesa, RamónGómez Gras, DavidTravieso Rodriguez, Jose AntonioBall burnishing is a comprehensive finishing process consisting on deforming plastically a certain surface by the action of a rolling sphere-shaped indenter. In this work, an AISI 1038 workpiece is burnished in two phases. The first phase covers the burnishing of a 10x10 mm patch, performed along the direction of the previous milling. The second pass is applied on the previous patch, following three different strategies, namely, parallel, perpendicular and at a 45-degrees angle with regards to that first burnishing direction. The comparison between the non-vibration assisted ball burnishing (NVABB) and vibration-assisted ball burnishing (VABB) effects is included in the study. To assess the influence of these strategies on the final roughness profile, an L9 Taguchi orthogonal array is designed, including as factors the vibrations amplitude, the burnishing force, and the lateral pass width. Surface roughness is measured and compared to determine the optimal burnishing orientation. The VABB process proves to be more effective in surface roughness improvement. Technical recommendations are given to select the best process parameters inside the tested levels for each factor. All burnishing strategy prove to have different effects on the surface, and should be selected according to the preferential burnishing direction and in service application of the part.Influences of trans-fatty acids on the tribological properties of plant oilshttp://hdl.handle.net/2117/106778
Influences of trans-fatty acids on the tribological properties of plant oils
Farré Lladós, Josep; Igartua, Amaya; Minami, Ichiro
A great challenge on tribology is the improvement of vegetable oils lubrication properties, which are environmentally friendly products, to replace long established lubricants based on mineral oils (petroleum). It is well known that some traditional additives used with mineral oils, such as organic sulfides, present antagonistic effects on vegetal oils on anti-wear boundary lubrication property. This work used natural rapeseed oil and sunflower oil to study the influence of the organic sulfides and the trans-fatty acids on the natural triglycerides. The tests used were a reciprocating motion test (SRV) and a unidirectional motion test (four ball test). The results show the same trend: the presence of trans isomers in the lubricant in combination with certain additives may significantly influence their boundary lubrication properties. As it is expected, octadecanethiol additive decrease the anti-wear performance although in combination with trans acid at low temperature keep the neat conditions and at high temperature the anti-wear properties are enhanced.
2017-07-25T07:49:47ZFarré Lladós, JosepIgartua, AmayaMinami, IchiroA great challenge on tribology is the improvement of vegetable oils lubrication properties, which are environmentally friendly products, to replace long established lubricants based on mineral oils (petroleum). It is well known that some traditional additives used with mineral oils, such as organic sulfides, present antagonistic effects on vegetal oils on anti-wear boundary lubrication property. This work used natural rapeseed oil and sunflower oil to study the influence of the organic sulfides and the trans-fatty acids on the natural triglycerides. The tests used were a reciprocating motion test (SRV) and a unidirectional motion test (four ball test). The results show the same trend: the presence of trans isomers in the lubricant in combination with certain additives may significantly influence their boundary lubrication properties. As it is expected, octadecanethiol additive decrease the anti-wear performance although in combination with trans acid at low temperature keep the neat conditions and at high temperature the anti-wear properties are enhanced.Control activo de transmisión de ruido causado por sobrevuelo de aeronaves transmitido por una apertura en fachadahttp://hdl.handle.net/2117/104939
Control activo de transmisión de ruido causado por sobrevuelo de aeronaves transmitido por una apertura en fachada
Pàmies Gómez, Teresa; Romeu Garbí, Jordi; Genesca Francitorra, Meritxell; Arcos Villamarín, Robert
This paper presents an experimental study based on the active control of sound transmission
through narrow opening of a casament window below. The main objective of the paper is to
demostrate the feasibility of the technique used to limit the loss of attenuation opening windows
and its application to the noise produced by overflying aircraft. The experimental window is
placed on the facade of a house near an airport and active control is configured to drop the
pressure in the opening using and adaptive feedforward only input and output, getting reduced
sound transmission whithout increase noise levels elsewhere.; Este artículo presenta un trabajo experimental basado en el control activo de la transmisión del
sonido mediante la apertura restringida de una ventana abatible inferior. Se desea demostrar
que la viabilidad de la técnica activa para limitar la pérdida de atenuación debida a la abertura
de ventanas y su aplicación sobre el ruido que produce el sobrevuelo de aeronaves. La ventana
experimental se coloca en la fachada de una vivienda cerca de un aeropuerto que esté sujeta a
dicho ruido mientras que el control activo está configurado para cancelar la presión en la
abertura utilizando un sistema adaptativo de alimentación directa de entrada y salida única.
2017-05-26T15:46:51ZPàmies Gómez, TeresaRomeu Garbí, JordiGenesca Francitorra, MeritxellArcos Villamarín, RobertThis paper presents an experimental study based on the active control of sound transmission
through narrow opening of a casament window below. The main objective of the paper is to
demostrate the feasibility of the technique used to limit the loss of attenuation opening windows
and its application to the noise produced by overflying aircraft. The experimental window is
placed on the facade of a house near an airport and active control is configured to drop the
pressure in the opening using and adaptive feedforward only input and output, getting reduced
sound transmission whithout increase noise levels elsewhere.
Este artículo presenta un trabajo experimental basado en el control activo de la transmisión del
sonido mediante la apertura restringida de una ventana abatible inferior. Se desea demostrar
que la viabilidad de la técnica activa para limitar la pérdida de atenuación debida a la abertura
de ventanas y su aplicación sobre el ruido que produce el sobrevuelo de aeronaves. La ventana
experimental se coloca en la fachada de una vivienda cerca de un aeropuerto que esté sujeta a
dicho ruido mientras que el control activo está configurado para cancelar la presión en la
abertura utilizando un sistema adaptativo de alimentación directa de entrada y salida única.Mapa acústico en zona acústica de régimen especial (ZARE) formada por actividades de ociohttp://hdl.handle.net/2117/104727
Mapa acústico en zona acústica de régimen especial (ZARE) formada por actividades de ocio
Jiménez Diaz, Santiago; Romeu Garbí, Jordi; Balanyà, Alguer
La Ley autonómica 16/2002 de protección contra la contaminación acústica permite la creación de zonas en las que, debido a las actividades que allí se desarrollan, se pueden superar los límites establecidos para el uso predominante de la zona. Sin embargo, se establece la obligación de aplicar un plan específico de medidas atenuadoras. Todo plan debe empezar por conocer la situación acústica existente, pero esto debe hacerse de modo que sea útil para el establecimiento de medidas correctoras. En este documento se aborda la realización de un mapa acústico zonal de un entorno en el que predomina el nivel sonoro que un conjunto de bares musicales abocan a la calle. Las únicas medidas correctoras posibles son o bien limitar el nivel sonoro dentro de las actividades o bien incrementar el aislamiento de las viviendas, pero para ello es necesario conocer la relación entre nivel interior de cada actividad y el nivel en fachada de los receptores. Para ello, se ha calculado el nivel de emisión de cada actividad mediante la norma UNE-EN 12354-4 y posteriormente se ha simulado la propagación exterior mediante un programa informático basado en el trazado de rayos. Mediante este modelo es posible reconocer la aportación de cada actividad a los distintos receptores lo que permitiría establecer límites a los niveles interiores de las actividades.; The regional law 16/2002 on protection against noise pollution allows the creation of areas
where, due to the activities that take place there, the limits for the predominant use of the area
can be overcomed. However, there is an obligation to implement a specific plan for reducing
measures. Every plan must start by knowing the existing noise situation, but this should be
done so as to be useful for the establishment of corrective measures. This paper deals with the
realization of a zonal noise map of an environment in which noise dominates a set of music bars
tripping over themselves to the street. The only possible corrective measures are either limit the
sound level in the activities or increase the insulation of homes, but this is necessary to know
the relationship between activity level and within each level in front of the receivers. To do this,
the power level of each activity is calculated by UNE-EN 12354-4 standard and its value has
been introduced in y a computer program based on ray tracing to calculate the noise levels at
the receivers. Using this model it is possible to recognize the contribution of each activity to
different receptors thus establishing limits on indoor levels of activities.
2017-05-22T18:00:30ZJiménez Diaz, SantiagoRomeu Garbí, JordiBalanyà, AlguerLa Ley autonómica 16/2002 de protección contra la contaminación acústica permite la creación de zonas en las que, debido a las actividades que allí se desarrollan, se pueden superar los límites establecidos para el uso predominante de la zona. Sin embargo, se establece la obligación de aplicar un plan específico de medidas atenuadoras. Todo plan debe empezar por conocer la situación acústica existente, pero esto debe hacerse de modo que sea útil para el establecimiento de medidas correctoras. En este documento se aborda la realización de un mapa acústico zonal de un entorno en el que predomina el nivel sonoro que un conjunto de bares musicales abocan a la calle. Las únicas medidas correctoras posibles son o bien limitar el nivel sonoro dentro de las actividades o bien incrementar el aislamiento de las viviendas, pero para ello es necesario conocer la relación entre nivel interior de cada actividad y el nivel en fachada de los receptores. Para ello, se ha calculado el nivel de emisión de cada actividad mediante la norma UNE-EN 12354-4 y posteriormente se ha simulado la propagación exterior mediante un programa informático basado en el trazado de rayos. Mediante este modelo es posible reconocer la aportación de cada actividad a los distintos receptores lo que permitiría establecer límites a los niveles interiores de las actividades.
The regional law 16/2002 on protection against noise pollution allows the creation of areas
where, due to the activities that take place there, the limits for the predominant use of the area
can be overcomed. However, there is an obligation to implement a specific plan for reducing
measures. Every plan must start by knowing the existing noise situation, but this should be
done so as to be useful for the establishment of corrective measures. This paper deals with the
realization of a zonal noise map of an environment in which noise dominates a set of music bars
tripping over themselves to the street. The only possible corrective measures are either limit the
sound level in the activities or increase the insulation of homes, but this is necessary to know
the relationship between activity level and within each level in front of the receivers. To do this,
the power level of each activity is calculated by UNE-EN 12354-4 standard and its value has
been introduced in y a computer program based on ray tracing to calculate the noise levels at
the receivers. Using this model it is possible to recognize the contribution of each activity to
different receptors thus establishing limits on indoor levels of activities.New lubrication device to minimize wear at the pitch gearhttp://hdl.handle.net/2117/103723
New lubrication device to minimize wear at the pitch gear
Farré Lladós, Josep; Casals Terré, Jasmina; Westerberg, Lars G.
2017-04-25T15:05:14ZFarré Lladós, JosepCasals Terré, JasminaWesterberg, Lars G.Study the efficiency of dynamic vibration absorbers in minimizing vibration power flow radiated from a double-deck tunnelhttp://hdl.handle.net/2117/103578
Study the efficiency of dynamic vibration absorbers in minimizing vibration power flow radiated from a double-deck tunnel
Noori, Behshad; Clot Razquin, Arnau; Arcos Villamarín, Robert; Romeu Garbí, Jordi
In recent years, underground train-induced ground-borne vibrations have become an important issue in heavily populated areas. As they cause not only the material failure but also serious human health problems, various vibration countermeasures are proposed and examined to control the train-induced ground-borne vibrations. The objective of this study is introducing Dynamic Vibration Absorber (DVA) as an innovative countermeasure in ground- borne vibration control field. DVAs are implemented on the interior floor of a double-deck tunnel which divides the structure into two halves and where trains circulate through both of them. The analytical model based on the receptance method is employed to calculate the mean power flow radiated by a double-deck circular tunnel. The model describes the dynamics of the interior floor using the thin plate theory and considers the Pipe-in-Pipe (PiP) model to describe the coupled tunnel-soil system. DVAs are coupled to the interior floor and their efficiency in minimizing radiated vibration power flow is studied. The effectiveness of DVAs depends on the parameters like their masses, damping ratios, natural frequencies and positions. Therefore, the most favorable design of DVAs requires optimal parameters. Genetic Algorithm (GA) is employed in order to find the optimum parameters of DVAs.
2017-04-20T13:13:47ZNoori, BehshadClot Razquin, ArnauArcos Villamarín, RobertRomeu Garbí, JordiIn recent years, underground train-induced ground-borne vibrations have become an important issue in heavily populated areas. As they cause not only the material failure but also serious human health problems, various vibration countermeasures are proposed and examined to control the train-induced ground-borne vibrations. The objective of this study is introducing Dynamic Vibration Absorber (DVA) as an innovative countermeasure in ground- borne vibration control field. DVAs are implemented on the interior floor of a double-deck tunnel which divides the structure into two halves and where trains circulate through both of them. The analytical model based on the receptance method is employed to calculate the mean power flow radiated by a double-deck circular tunnel. The model describes the dynamics of the interior floor using the thin plate theory and considers the Pipe-in-Pipe (PiP) model to describe the coupled tunnel-soil system. DVAs are coupled to the interior floor and their efficiency in minimizing radiated vibration power flow is studied. The effectiveness of DVAs depends on the parameters like their masses, damping ratios, natural frequencies and positions. Therefore, the most favorable design of DVAs requires optimal parameters. Genetic Algorithm (GA) is employed in order to find the optimum parameters of DVAs.Optimization of dynamic vibration absorbers placed on the tunnel interior surface to mitigate underground railway-induced vibrationhttp://hdl.handle.net/2117/103556
Optimization of dynamic vibration absorbers placed on the tunnel interior surface to mitigate underground railway-induced vibration
Noori, Beshshad; Cubría, Victor; Arcos Villamarín, Robert; Clot Razquin, Arnau; Romeu Garbí, Jordi
In the present study, dynamic vibration absorber (DVA) has been introduced as an innovative countermeasure in the field of railway-induced vibration. The Pipe-in-Pipe (PiP) model and Green's functions for a two-and-a-half dimensional (2.5D) elastodynamic problem in a full- and half-space have been employed to find the response of the tunnel embedded in a homogeneous half-space due to a harmonic load. DVAs have been coupled to the tunnel interior surface. The effectiveness of DVAs depends on the mass, damping ratio, natural frequency and their distribution. Therefore, an optimization algorithm has been developed to find the optimum parameters of the DVAs, which are those that minimize the vibration levels at the ground surface. Evaluating the efficiency of the optimal DVAs shows that they are an efficient countermeasure to mitigate underground railway-induced vibration.
2017-04-19T15:26:16ZNoori, BeshshadCubría, VictorArcos Villamarín, RobertClot Razquin, ArnauRomeu Garbí, JordiIn the present study, dynamic vibration absorber (DVA) has been introduced as an innovative countermeasure in the field of railway-induced vibration. The Pipe-in-Pipe (PiP) model and Green's functions for a two-and-a-half dimensional (2.5D) elastodynamic problem in a full- and half-space have been employed to find the response of the tunnel embedded in a homogeneous half-space due to a harmonic load. DVAs have been coupled to the tunnel interior surface. The effectiveness of DVAs depends on the mass, damping ratio, natural frequency and their distribution. Therefore, an optimization algorithm has been developed to find the optimum parameters of the DVAs, which are those that minimize the vibration levels at the ground surface. Evaluating the efficiency of the optimal DVAs shows that they are an efficient countermeasure to mitigate underground railway-induced vibration.Prediction of the isolation efficiency of vibration countermeasures for a double-deck tunnelhttp://hdl.handle.net/2117/103555
Prediction of the isolation efficiency of vibration countermeasures for a double-deck tunnel
Clot Razquin, Arnau; Arcos Villamarín, Robert; Romeu Garbí, Jordi; Noori, Beshshad
Double-deck tunnels are an innovative tunnel design that has been recently implemented in some underground railways and metro lines worldwide. However, due to the complexity of this type of structures, its dynamic response has not yet been fully comprehended. This lack of understanding complicates the design of efficient vibration isolation countermeasures for them. Therefore, proper models for predicting the vibration impact of double-deck tunnels are highly needed. The aim of this paper is to present, on the one hand, an efficient model of a railway superstructure implemented in a double-deck tunnel and, on the other, to study how the vibration impact of this structure is affected by the addition of an elastomeric mat between the interior floor-tunnel contact and by modifications of the rail pads stiffness and damping values. In both cases, the results are presented in terms of the energy flow radiated upwards by the structure when harmonic moving loads circulate along the rails.
2017-04-19T15:11:03ZClot Razquin, ArnauArcos Villamarín, RobertRomeu Garbí, JordiNoori, BeshshadDouble-deck tunnels are an innovative tunnel design that has been recently implemented in some underground railways and metro lines worldwide. However, due to the complexity of this type of structures, its dynamic response has not yet been fully comprehended. This lack of understanding complicates the design of efficient vibration isolation countermeasures for them. Therefore, proper models for predicting the vibration impact of double-deck tunnels are highly needed. The aim of this paper is to present, on the one hand, an efficient model of a railway superstructure implemented in a double-deck tunnel and, on the other, to study how the vibration impact of this structure is affected by the addition of an elastomeric mat between the interior floor-tunnel contact and by modifications of the rail pads stiffness and damping values. In both cases, the results are presented in terms of the energy flow radiated upwards by the structure when harmonic moving loads circulate along the rails.Methodology for the experimental evaluation of frequency response functions in the frame of railway-induced or construction-induced groundbourne vibrationhttp://hdl.handle.net/2117/103553
Methodology for the experimental evaluation of frequency response functions in the frame of railway-induced or construction-induced groundbourne vibration
Arcos Villamarín, Robert; Sans Garcia, Jorge; Romeu Garbí, Jordi; Clot Razquin, Arnau; Cardona Gonyalons, Joan; Oregui, Maider
In this paper, a methodology for the experimental evaluation of mechanical vibration frequency response functions in the framework of groundbourne railway-induced and construction-induced vibration predictions is presented. This methodology is based on a device specifically designed for the excitation of railway superstructures. The device can be used also to excite the ground with the aim of obtaining ground/building frequency response functions. The resulting frequency response functions can be used to feed prediction empirical models with specific in situ results or to characterize the system by performing an inversion process over a theoretical model of it, among other applications. Two examples of this methodology applied for the experimental determination of frequency response functions and subsequent system characterization are presented.
2017-04-19T13:57:03ZArcos Villamarín, RobertSans Garcia, JorgeRomeu Garbí, JordiClot Razquin, ArnauCardona Gonyalons, JoanOregui, MaiderIn this paper, a methodology for the experimental evaluation of mechanical vibration frequency response functions in the framework of groundbourne railway-induced and construction-induced vibration predictions is presented. This methodology is based on a device specifically designed for the excitation of railway superstructures. The device can be used also to excite the ground with the aim of obtaining ground/building frequency response functions. The resulting frequency response functions can be used to feed prediction empirical models with specific in situ results or to characterize the system by performing an inversion process over a theoretical model of it, among other applications. Two examples of this methodology applied for the experimental determination of frequency response functions and subsequent system characterization are presented.